Silicon monolithic microchannel-cooled laser diode array

Abstract

A monolithic microchannel-cooled laser diode array is demonstrated that allows multiple diode-bar mounting with negligible thermal cross talk. The heat sink comprises two main components: a wet-etched Si layer that is anodically bonded to a machined glass block. The continuous wave (cw) thermal resistance of the 10 bar diode array is 0.032 °C/W, which matches the performance of discrete microchannel-cooled arrays. Up to 1.5 kW/cm2 is achieved cw at an emission wavelength of ∼808 nm. Collimation of a diode array using a monolithic lens frame produced a 7.5 mrad divergence angle by a single active alignment. This diode array offers high average power/brightness in a simple, rugged, scalable architecture that is suitable for large two-dimensional areas.

Numerical analysis of heat transfer in a manifold microchannel heat sink with high efficient copper heat spreader

“…Transverse channels were electroplated on the bottom surface of the heat spreader and placed between each two parallel longitudinal V-channels in silicon substrate. The design provides a local high efficient heat transfer mode (Skidmore et al 2000;Xu et al 2005), which decreases the temperature difference along the flow direction and improves heat transfer efficiency of the microchannel heat sink greatly. In addition, it will be more suitable for integrated fabrication.…”

“…Unger et al (1999) developed a CVD-diamond heat spreader exhibiting a high thermal conductivity to improve lateral spreading of heat from the active regions, and with the microchannel cooling carrier, high heat transfer characteristics were obtained. Skidmore et al (2000) demonstrated a microchannel heat sink comprising a wetetched Si layer that is anodically bonded to a machined glass block. The intersecting channels provide a larger heat transfer area to minimize the stagnant boundary layer of coolant, which increases the heat transfer efficiency significantly.…”

Scalable high-power (>1kW/cm^2) diode laser stacks based on silicon monolithic micro-channel coolers

“…2,3 Following these recommendations one can expect a cooler lifetime ~10-20Khrs. In the discussion that follows, we review a technology based on micro-channels fabricated in Silicon 4,5 . We believe that this technology offers several key advantages over the existing copper MCCP technology, such as corrosion resistance, electrical isolation to the cooling water, minimal water sealing surfaces, manufacturing simplicity and power scalability.…”

The Mercury Project: A High Average Power, Gas-Cooled Laser for Inertial Fusion Energy Development

“…The diode arrays heavily leverage mass production and commercial markets for diodes. With the commercialization of the LLNL diode packaging 3 by Coherent Inc, an entire high brightness array could be procured. The arrays already being used in the laser meet all of the basic requirements (see table 1) except wallplug efficiency (45 % versus 50 %).…”